The present invention relates to a lens for projection, and an image display device. The image display device can be executed as a projector device.
In recent years, projector devices have been widely used for business presentations, educational use at school, and family use.
An image display element which displays an image to be projected in an enlarged manner on an image display surface is called a light valve; however, various types of image display elements such as a liquid crystal panel and the like are known.
In recent years, a micromirror device as typified by a digital micromirror device (DMD) manufactured by Texas Instruments Incorporated. has attracted attention as a light valve.
Needless to say, a lens for projection is preferably applicable to various light valves.
In addition, there is a demand for the lens for projection to be wide-angle.
As a projector device having a wide angle of view, a projection optical system having a combination of a lens system and a reflecting mirror is known.
In a projection optical system including a reflecting mirror, the projection mirror tends to become larger, and therefore, ingenuity is needed for miniaturization of a projector device.
In a case where a projection optical system is constituted of a lens system, ingenuity is needed for a wide angle of view.
As a lens for projection having a wide angle of view and a fixed focus, various types of lenses have been conventionally proposed.
Above all, Japanese Patent Number 4847110 discloses a high-performance lens for projection constituted of two lens groups in which distortion is suppressed to −1.5%, and a half angle of view of 56 degrees is achieved.
Recently, shortening a distance between a projector device and a screen more and displaying a larger-sized projection image have been demanded.
In order to achieve the above, achievement of a lens for projection having a wider angle of view is desired.